1. Field
Example embodiments relate to a semiconductor device. Other example embodiments relate to an inverter, a logic circuit including the inverter and methods of fabricating the same.
2. Description of the Related Art
Logic circuits (e.g., not-and (NAND) circuits and not-or (NOR) circuits) are used in various semiconductor integrated circuits (e.g., dynamic random access memories (DRAM), static random access memories (SRAM), non-volatile memories, liquid crystal display (LCD) devices, organic light emitting display (OLED) devices) and the like. An inverter is the base of the logic circuits.
In general, a silicon (Si)-based inverter may be a complementary metal-oxide semiconductor (CMOS) inverter, which includes both an n-channel metal-oxide semiconductor (NMOS) transistor and a p-channel metal-oxide semiconductor (PMOS) transistor. If a silicon (Si) layer is used as a channel layer, the NMOS or the PMOS transistor may be easily fabricated by doping different kinds of elements into the channel layer. Thus, it may be easier to fabricate the CMOS inverter. For example, if a III-group element (e.g., boron (B)) is doped into the Si layer, the Si layer becomes the p-channel layer.
If the channel layer is formed of an oxide semiconductor, it may be difficult to form the p-channel layer due to the properties of the material formed of the oxide semiconductor. Most of the channel layers formed of the oxide semiconductor are n-channel layers. If a transistor having a channel layer formed of an oxide semiconductor is used, it may be difficult to form the inverter having both the n-channel transistor and the p-channel transistor.